Question: Indexed or variable named filenames.

While these things are a walk in the park with languages like C and system administration languages like bash, the maple file IO is really a bit wanting

I tried, but nowhere in the manual could I find how to use a variable in a filename.

As an example with bash,   you can assign a value to a variable say Ver=01.

The program code contains the filename as
filename$Ver.txt,
and upon execution of the file saved, it is saved as filename01.txt .
Where it replaced the variable with its value in the saved file.

There seems to be no such thing in Maple I could find.
If it exists, it must be so obscure that normal manual searches cannot find it.

So, how do you save a file using a variable in the filename, which then uses the value of the variable in the saved filename. ?
This is basically a prerequisite e.g. for server based maple doing large datasets, so maple must be capable doing it.